Ricinus communis, castor oil plant

Summary

Usually described as absolutely deadly in the tiniest of amounts; 50,000 tonnes a year
being produced; usually said to be reasonably easy to extract from the plant; so why
has ricin killed hardly anyone since 1978?

'Poisonous Plants 1-2-1' video

This short video summarising the story of the castor oil plant is just one of
a series.

Family

Euphorbiaceae

Meaning of the Name

Ricinus
A circular definition is usually given i.e. ‘ricinus’ means ‘tick’
because the skin of the castor beans looks like a tick. But there is
a tick called iloxedes ricinus named because its skin looks like a
castor bean. Possibly from the Latin ‘ri’, ‘thing’ and ‘cinus’,
‘destruction’, ‘the dead’, ‘ruin’, thus, the thing which brings
death.

communis
Common

Common Names and Synonyms

castor bean plant, true castor oil plant, hand of Christ (palma
Christi). Fatsia japonica, the false castor oil plant, is often sold
as 'castor oil plant' though the two have nothing in common apart
from their appearance.

How Poisonous, How Harmful?

Ricinus communis,
castor oil plant

As quite a strong laxative, castor oil can be the cause of harm,
especially if it is ingested accidentally as a result of spray from
its use as a lubricant, but it is the substance left in the residue
after the beans have been crushed to produce the oil which makes
Ricinus communis such a notorious plant. Because those
residues contain ricin.

Ricin, a simple protein, is believed to be one of the most toxic
naturally occurring substances and is often mentioned as a potential
terrorist weapon for causing mass murder in spite of all evidence to
the contrary. The plant also contains
Ricinus Communis Agglutin (RCA) which causes increased coagulation.

If ingested, it causes vomiting which in many cases expels the
poison and prevents death. If injected or inhaled it causes stomach
pain, dehydration and destroys the main internal organs. With no
antidote, treatment relies on symptomatic support and the use of
heart lung machines, kidney dialysis, etc. After 3-5 days symptoms
diminish though death may take about the same time to occur.

But, though ricin is extremely poisonous it actually does little
harm. Around one million tons of castor beans are processed each
year for castor oil production leaving the waste pulp with up to
50,000 tons of ricin in it. And, yet, finding instances of ricin
poisoning is not an easy task.

So how is it that this exceptionally toxic substance fails to
achieve its harmful potential?

Ricinus communis,
castor oil plant

There are three main ways to administer a poison; ingestion,
inhalation or injection. Val McDermid in her book ‘Beneath the
Bleeding’ has found a fourth, see the box below, but that is unlikely to
become common.

As above, ricin is extremely emetic, if ingested. A 1985
report from the Emory University School of Medicine and the Georgia
Poison Control Center examined 751 cases of accidental ricin
ingestion during the previous 85 years. They found only 15 deaths (1.9%
mortality) in these cases, an indication of the problems of causing
death by ingestion of ricin. The researchers went on to look at
those deaths in more detail and concluded that, with
modern symptomatic support methods, a number of them could have been
avoided. They estimate that, today, fatality from ingestion is
likely to be around 0.4%. Feeding ricin to the masses is, thus, not
likely to be an efficient way to cause multiple deaths.

Experiments have shown that inhalation of even tiny amounts of
ricin is fatal and this leads to many stories of plans to spray
ricin into the general population, especially on underground train
networks. What these scare stories ignore is that, in the
experiments, the animals used were fitted with face masks and
forced to inhale the ricin. Ricin is an extremely large
molecule and, normally, forms large particles which fall to the ground quickly, especially in the
presence of any draught. Its use as an aerosol spray would be
unlikely to produce any deaths.

A paper published in
'Environment International' in November 2009 by Schep at al,
contains an extensive review of the literature on ricin and
points out that to have a serious effect by inhalation ricin
powder would need to be milled to a very small particle size.
The authors say this may be possible for a rogue government to
do but is not something small terrorist groups would be able to
achieve.

Ripening fruits of Ricinus communis

The authors do say that there is a very small possible that
terrorists could produce enough ricin to poison a small water
supply and cause non-fatal symptoms of poisoning. Such an event
could cause substantial panic given the media's ill-informed
paranoia about ricin.

The Hampstead and Highgate Express published the obituary of
Professor John Henry, described as Britain's best known
toxicologist. Prof Henry was an expert witness in the Leah Betts
ecstasy death
case and identified the poison, dioxin, used on Victor Yushchenko,
just from a photograph. According to the newspaper he also
‘diffused tabloid hysteria about the planned ricin attack on the
London underground by pointing out that London commuters could in
fact swim in ricin without suffering any harm - it was only fatal if
injected into the bloodstream.’

So, for ricin to be as actually harmful as it is theoretically,
it must get into the bloodstream and, unless terrorists find a way
to get people to line up and receive an injection, the sad fact is
that there are plenty of better weapons available to the renegade
government or terrorist wishing to mount an attack.

In an elliptical sort of way, ricin can be said to have
contributed to tens of thousands of deaths. In January 2003, as
the Bush government was trying to build its case to invade Iraq,
British police raided premises in North London and, then and
later, arrested nine men. They were said to be a terrorist
cell and, it was alleged, the premises raided were being used as
a 'factory' to produce biological weapons. Samples were removed
which were thought to be ricin. In the event, no ricin was found
and eight of the nine men charged were freed after four were
found not guilty and the charges against another four were
dropped. The ninth, Kamel Bourgass, was convicted of 'conspiracy
to cause a public nuisance by the use of poisons' having,
earlier, been convicted of the murder of a police
officer attempting to arrest him.

The importance of this event, however, is that on 5th
February, 2003 US Secretary of State, Colin Powell, gave a
speech to the UN Security Council arguing for a resolution in
support of war on Iraq. In this speech, he referred to
intelligence reports pointing to the intention of Iraqi backed
terrorists to launch 'poison and explosive' attacks in Europe
and said that the unearthing of a terrorist cell in Britain in
January proved that this intelligence was valid.

Though Powell did not, specifically, identify the so-called
'ricin plot', it didn't take long for the press to make the
connection. (It is a common ploy to give journalists enough
information so that they find data for themselves which removes
their scepticism about information being fed to them.) This apparent confirmation of the veracity of US
intelligence reports is believed to have been key to the
decision to invade Iraq. It is widely believed that UK Prime
Minister, Tony Blair, himself brought the 'ricin plot' to the
attention of George Bush resulting in its inclusion in Colin
Powell's evidence.

To this day, some writers continue to talk about ricin as a
potential bioterrorism weapon insisting that Iraq was producing
ricin but completely ignoring the evidence that this production
was small-scale, terminated in the mid-1990s and was for use in
assassinations; its use as a weapon of mass destruction having
been found to be impractical. As recently as January 2013, the
press reports on a case concerning whether one of the eight men
arrested in 2003 could be deported contained references to the
'ricin plot' in spite of there being no such thing.

Watch a Video about Ricin

Click in the window above to watch a ten minute video about
Ricinus communis and ricin.

Incidents

The best known incident of ricin poisoning was the 'umbrella murder' of Georgi Markov in London in 1978. Markov was
waiting for a bus when he felt a sting to the back of his thigh. He
looked round to see a man picking up an umbrella. The man apologised
in accented English and got into a waiting taxi. Following his, death three days
later Markov was found to have a small pellet imbedded in his thigh
with holes drilled in it. Though no metabolites of ricin were
detected, experts concluded that the most likely cause of the
poisoning was that a small amount of
ricin had been present in the pellet, held in place by a covering of
a substance that would melt at body temperature. This 'best guess'
is reinforced by the discovery of antibodies in Vladimir Kostov (see
next paragraph). The British press
decided that the umbrella had been used as the means of delivering
the pellet and the story of the 'umbrella murder' entered folklore.

Flowering Ricinus communis, castor oil plant

What is less well known is that a couple of week’s before
Markov’s death, Vladimir Kostov, a fellow Bulgarian dissident living
in Paris was taken ill but recovered after 12 days. When the
possible cause of Markov’s death was becoming clear Kostov was
x-rayed and found to have a tiny pellet still imbedded in his
flesh. The significant difference seems to be that Kostov was 'shot'
in the back through several layers of clothing. It would appear that this slowed the pellet enough for it
not to penetrate far enough for the poison to get fully into his
bloodstream. It could also be that the protective coating had
already failed so that the ricin leaked away or that it failed to
fully dissolve. Kostov was, however, found to have ricin antibodies
in his bloodstream so he had been exposed to the poison. There was
never any mention of an umbrella in the Kostov case.

The circumstances of Kostov's poisoning help to construct the
most likely scenario for the attack on Markov. Dropping an
umbrella would have served three purposes for the murderer.
First, he would have been able to approach more closely to
Markov than would have seemed normal if he were not retrieving a
dropped item. Second, his lower body position would give him
access to Markov's thigh where only one layer of material needed
to be penetrated. And third, like any magician, the murderer was
creating a diversion so that anybody watching would be focussing
on the hand picking up the umbrella and not looking at the other
hand, thought to have contained a small modified air pistol
using compressed air to fire the pellet.

The umbrella story was given new credence, apparently, in the
1990s when a former KGB officer said that he had dealt with the
request from the Bulgarian Secret Service for help in killing
Markov and that Andropov, the then Soviet leader, had authorised
technical assistance but not active involvement. The KGB officer
said he knew where the KGB had designed and built the modified
umbrella. This was only a small part of the officers stories
about his time in the KGB. Those who have studied his writings
say that many things do not stand up to scrutiny and some can be
found in spy fiction. On the Markov case, the officer said
Kostov had been attacked after Markov.

Like the ricin plot that wasn't, the press continues to refer
to Markov's killing as the 'umbrella murder'. As mentioned
above, there has never been any suggestion that an umbrella
played any role in the Kostov attack. It would seem to be very
odd for the KGB to develop a weapon for delivering a small
pellet of ricin into Kostov's back and then develop another
weapon to use on Markov.

A more recent 'incident' turns out not to be an incident at
all. In late 2010, CBS reported that the USA's Department for
Homeland Security (DHS) had issued a warning about the
possibility of terrorists contaminating the food in restaurants
and hotels. This rapidly got re-reported by other media and soon
became an actual plot. These days, articles about ricin talk
about 'the plot to poison thousands reported by the DHS' and the
like.

The DHS refuses to give a full explanation of what happened
though it does say it has never issued a public warning about
such a plot. As far as can be assessed, it seems that the DHS
gave a routine briefing to security managers involved in the
hospitality industry about what to look out for in the event of
an attempt to cause poisoning via contamination of food served
to the public. Word of this event reached the media who then
created the 'plot'.

As a result, a journalist for a proper scientific publication
writes about 'a recent bioterrorism attack plot targeting US
hotels and restaurants at multiple locations'. (I won't
perpetuate the myth by linking to the piece.)

A letter to the British Medical Journal, in 1905, reports the
case of a 28-year old man who ingested one castor bean and suffered
immediate burning of the mouth and eyes followed by collapse. He
was admitted to hospital with very shallow breathing and no
measurable pulse. He had no diarrhoea and was, during his stay,
treated to relieve constipation. He received emetics and
stimulants and, by the next day, his pulse and respiration were
normal. He remained in hospital under observation for a few days
but was released fully recovered.

The symptoms described, the rapidity of their onset, the
absence of abdominal symptoms and diarrhoea and the equally
rapid recovery cast doubt over whether the poisoning agent was
correctly identified leading to correspondence on both sides of
the argument but no conclusive resolution.

The paper by Schep et al referred to above does give details
of deaths due to the injection of ricin. In all but one of these
the deaths were suicide. The only reported murder was part of a
murder suicide reported, briefly, in 2004.

A very elderly man recounted his experience when a prisoner of
the Japanese in Thailand during WWII. He and about 200 other men
were out on a work party when they came across a large number of
bushes all bearing fruit. They fell upon them and ate the fruit
which was later identified as from the castor oil plant. All
suffered severe diarrhoea and two died, though whether as a direct
result of ricin or simply due to the effect of the diarrhoea can
never be established.

Fruit of Ricinus communis,
castor oil plant

An August 2009 paper written by doctors in Belgium reported
on the case of a 49 year-old man who committed suicide by
injecting himself with ricin. He was admitted to hospital 24
hours after the injection and died nine hours later in spite of
symptomatic intensive care support. Death resulted from
multi-organ failure following nausea, vomiting, diarrhoea,
vertigo and muscular pain.

Incidents related to the overuse of castor oil are more
light-hearted for the reader though not for the participants.

An Australian visitor to the Alnwick Garden Poison Garden talked
about a man who suffered serious diarrhoea which cleared up quickly
if he took time off work but returned when he returned to work. She
was working at a poison information centre and was asked if she
could suggest any possible causes. Acting on her advice it was
discovered that the machine which the man used at work was faulty
causing a fine mist of lubricating oil to be present in the air.
The lubricant was castor oil. As soon as the machine was repaired
the man’s diarrhoea cleared up for good.

Early aircraft, like the Sopwith Camel, used a rotary engine
where castor oil was used as a lubricant. The oil would mix with
the fuel/air combination in the cylinder but would only be partly
burnt. The exhaust from these engines would, therefore, contain an
amount of unburnt castor oil. As well as making the engines oil
hungry and, therefore, increasing the need for maintenance, this
unburnt oil was the cause of dirty streaks along the fuselage. It
was said that this could cause visibility problems for the pilot and
so cowlings were installed to direct the exhaust flow under the
fuselage. There is no mention, other than anecdotally, of the other
problem which could be expected by exposing pilots to castor
oil-laden fumes.

Folklore and Facts

Val McDermid’s book ‘Beneath the Bleeding’ is
the story of a serial poisoner who uses various plant extracts as
his murder weapons. The case discussed in most detail involves
ricin being applied to the body, during a sexual encounter, in a
place where it might reasonably be expected to enter the
bloodstream.

Let's just say that, had the victim survived the poisoning, they
would have found sitting down uncomfortable.

In spite of the lack of any actual incidents and the near
impossibility of using ricin to mount a terrorist attack, the plant
is viewed with some suspicion. An American said that she had
purchased 6ozs of castor beans online after being told that they
would harm moles. A couple of days after the beans arrived she was
visited by an FBI agent who knew a great deal about her and wanted
to know what she was planning to do with the beans.

Another American said that she had buried castor beans all around
the perimeter of her property because she had been told this would
keep gophers out. Online sources talk about putting castor beans
down gopher holes in the hope they will eat them or growing the
plant around the perimeter as its roots are said to be toxic to
gophers. An American Cable TV gardening programme, broadcast in
November 2004, talked about a new product made by mixing castor oil
with ground corncobs and soap and milling the mixture into granules.
The granules release the castor oil smell when they get wet and this
is said to repel gophers and moles without hurting them. It should
be said that other sites say there is no evidence for efficacy of
any of these methods of gopher control.

The status of ricin as a potential terrorist weapon is an
example of the continuing development of plant folklore which
many people think of as somehow being set in past times. Whether
through ignorance or a desire to misdirect potential terrorists,
the US authorities, in particular, continue to put ricin forward
as something to be feared in ways which almost parallel old
beliefs about the devil and
Atropa belladonna,
deadly nightshade.

It is, frequently, stated that ricin can be easily extracted
from castor beans and that recipes are readily available on the
Internet. The majority of these recipes can be traced back to a
bulletin board favoured by school and college students (almost
exclusively boys) in the 1990s. In fact, the recipe does no more
that dry the castor bean mash left after the oil has been
pressed. The level of knowledge of the author can be seen from
his description of castor oil as a cough medicine and his
statement that he doesn't know where to get castor beans.

Ricin is, also, not
particularly stable and the crude extraction methods proposed
would likely destroy a large proportion of the toxin.

Sources - Papyrus Ebers

The Ebers Papyrus, is named after the Egyptologist who first
possessed it after its discovery in the mid 19th century. It
has been dated to around 1500BC but, since it is clearly a
collection of well-known remedies rather than a new work, it is
taken to show that the Egyptians had a well developed system of
medicine possibly as far back as the First Dynasty, 3400BC. It is
unclear whether there was a single author or several people
contributed to its production.

Perhaps its best known remedy is the use of opium to help a baby go
to sleep.

The fascination with ricin as a weapon was, again,
demonstrated in June 2009 when the UK's National Archive
declassified a 1945 report entitled 'The Use of Chemical Darts
from the Air'. This report looked at work to develop a system
for dropping small poisoned darts directly onto enemy troops.
According to press reports covering the release of the report,
the poison to be used was 'probably anthrax or ricin'. The
report actually says that for such a weapons system to be
effective it must disable immediately and kill within fifteen
minutes. An appendix says that a compound designated T.1123
which is a nerve agent has been selected after a number of
unnamed substances were tested. A substance, designated only as
'X' is given as a possible alternative though its effects are
not immediate. It is reported that 'X' causes vision impairment,
paralysis and death within 12 hours.

It is quite clear that ricin does not meet the criteria
specified and is neither compound T.1123 nor substance 'X' but,
it appears, the media are so obsessed with ricin that they
cannot bring themselves to report a chemical/biological weapons
story without including ricin as the villain of the piece.

Hundreds of seedpods on a plant in Gozo

The ancient Egyptians were familiar with the ‘castor oil tree’
and made extensive use of castor oil and other parts of the plant in
the remedies collected in the Ebers Papyrus. It appears in over 100
prescriptions. As might be expected it was drunk as a cure for
constipation but it was also rubbed on the head to cure headaches or
to promote growth of hair for a woman. In these instances it is
used on its own but it also gets mixed with all manner of other
items. With yeast and water, it would cure roundworm. With red
lead it was capable of curing herpes on the face. The leaves, mixed
with honey and ‘clay from a statue’ and applied as a poultice would
treat a ‘flow of matter’ from both eyes.

Though I haven't read anything on the subject, I have noticed
that the plant seems to have disappeared from local authority
plantings. I hadn't seen Ricinus communis in a municipal
flowerbed or tub for about three years when, in 2017, I
holidayed on the Maltese island of Gozo and saw a massive plant
growing wild adjacent to a seating area at the roadside in the
middle of a village. One can only wonder what the British press
would make of seeing the hundreds of seed pods on this single
plant well within reach of anyone passing.

Earlier Blog Entries;

You can read more about Ricinus communis and ricin in these blog
entries (most recent first);